the equation of a projectile can be written as http://alt1.mathlinks.ro/Forum/latex...d2f86b50c3.gif

(i)show that the point http://alt1.mathlinks.ro/Forum/latex...534eee0c94.gifcan be hit by firing at two different angles http://alt2.mathlinks.ro/Forum/latex...3a7a5a1a6f.gif and http://alt1.mathlinks.ro/Forum/latex...5913615030.gif if http://alt2.mathlinks.ro/Forum/latex...787d485961.gif

(ii) show that no point ABOVE the x axis can be hit by firing at two different angles such that http://alt1.mathlinks.ro/Forum/latex...df604791bf.gif and http://alt2.mathlinks.ro/Forum/latex...7ce6c81bd9.gif

i have completed part one but i have no idea how to approach part two